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In recent times, the potential toxicity of amalgam (silver fillings) has become an increasing concern among people, who also increasingly prefer less conspicuous fillings. As a result, composite (white fillings) materials have been increasingly used to repair dental decay. In the US, over 122 million composite tooth restorations are carried out every year.2
Synthetic resins are generally used for composite fillings, but they are very soft compared to natural tooth material, making them more vulnerable to failure than amalgam (synthetic resins last for 6-10 years, whereas amalgam lasts for several decades). However, all fillings are susceptible to failure at some point of time when they shrink or crack away from the tooth and create gaps to harbor food debris and bacteria, further increasing the risk of tooth decay. Secondary caries taking place at the margins are the major reason for replacement fillings.
Intensive research is going on to develop a more durable filling material for repairing dental decay without compromising the aesthetic value. Bioactive glass is a biocompatible material and is already used in many biomedical applications. Therefore, its potential use in dentistry was investigated. The role of bioactive glass as a tooth filling material is discussed in this article.
What is Bioactive Glass?
Glass does not produce an immune response and therefore, by virtue of its low weight and high strength, has been extensively used in various biomedical applications, wound healing, bone regeneration, and bone tissue engineering.4 Bioactive glass is a form of crushed glass capable of bonding to either soft or hard tissue and also showing antimicrobial activity.
High purity chemicals, such as calcium oxide, silicon oxide, and phosphorus oxide, are smelted in ceramic crucibles to make bioactive glass.5 They are available as powders and discs with specific compositions and varying sizes.6 Also, to meet specific requirements, the physical properties of glass can be customized by modifying its structure and composition.5
Dental Bioactive Glass Composites
Following the successful role of bioactive glass in orthopedic applications, its potential use was explored in dentistry applications. The material has been shown to be advantageous in the repair of periodontal defects.4
The demonstrated high strength and the observed antimicrobial activity of bioactive glass make it a potential candidate for dental fillings. Tooth fillings using bioactive glass should improve the durability of composite filling materials and hinder secondary tooth decay by suppressing bacterial colonization. Moreover, it was hypothesized that minerals may also be supplied by the bioactive glass to strengthen the damaged tooth surface.
Recent studies of bioactive glass as a dental filling have demonstrated that such extrapolations to dentistry are indeed correct. Mineral formation in the dentin is enhanced when bioactive glass is added to dental filling materials, promoting remineralization of dental caries7 and improving the mechanical properties of tooth fillings in an aqueous environment.8
In a recent study, it has been shown that the addition of bioactive glass filler to composite filling materials helps make restorations that are less susceptible to bacterial penetration.9 The proportion of the gap depth colonized with bacteria was 61% for fillings made from a filler containing bioactive glass compared with 100% for those made from the traditional filler.
These results conclude that the use of a composite filling material containing bioactive glass may enhance the durability of composite fillings and reduce the occurrence of secondary tooth decay at restoration margins.
In dentistry, secondary tooth decay at the site of restorations still remains a challenge. Dental fillings using bioactive glass composites have better strength and reduced bacterial colonization. As a result, the restoration will have a reduced rate of decay and increased service life. Hence, the incorporation of bioactive glass to dental filler materials shows promise to offer a less problematic solution to patients requiring dental restorations.
This type of glass is only beginning to see use in dentistry, and our research shows it may be very promising for tooth fillings. The bacteria in the mouth that help cause cavities don’t seem to like this type of glass and are less likely to colonize on fillings that incorporate it. This could have a significant impact on the future of dentistry.
Jamie Kruzic, Professor and Expert, Advanced Structural and Biomaterials, The Oregon State University College of Engineering
- 1.National Institutes of Health. NIDCR Data & Statistics. Dental Caries (Tooth Decay) in Adults (Age 20 to 64). Available at: https://www.nidcr.nih.gov/DataStatistics/FindDataByTopic/DentalCaries/DentalCariesAdults20to64.htm
- Stauth D. New study: Bioactive glass prolongs the life of tooth fillings Dentistry IQ, 5 January 2106. Available at http://www.dentistryiq.com/articles/2016/01/new-study-bioactive-glass-prolongs-the-life-of-tooth-fillings.html
- Marks LAM, et al. Dyract versus Tytin class II restorations in primary molars: 36 months evaluation. Caries Research. 1999;33:387–392.
- Rahaman MN, et al. Bioactive glass in tissue engineering. Acta Biomaterialia 2011;7:2355 2373.
- Brauer DS. Bioactive Glasses—Structure and Properties. Angew Chem Int Ed 2015;54: 4160–4181.
- Mo Sci Corporation website. http://www.mo-sci.com/en/products
- Prabhakar AR, et al Comparative Evaluation of the Remineralizing Effects and Surface Micro hardness of Glass Ionomer Cements Containing Bioactive Glass (S53P4):An in vitro Study. Int J Clin Pediatr Dent. 2010 May-Aug;3(2):69-77. doi: 10.5005/jp-journals-10005-1057. Available at https://www.ncbi.nlm.nih.gov/pubmed/27507915.
- Chatzistavrou X, et al. Fabrication and characterization of bioactive and antibacterial composites for dental applications. Acta Biomater. 2014;10:3723–3732. Available at https://www.ncbi.nlm.nih.gov/pubmed/24050766
- Khvostenko D, et al. Bioactive glass fillers reduce bacterial penetration into marginal gaps for composite restorations. Dental materials 2016;32(1):73–81. Available at http://www.demajournal.com/article/S0109-5641(15)00437-6/pdf
This information has been sourced, reviewed and adapted from materials provided by Mo-Sci Corp.
For more information on this source, please visit Mo-Sci Corp.